This invention relates to an electronic switching arrangement for energizing from a direct-current source an electric motor of the type consisting of a stator with a polyphase winding and a permanently magnetised rotor coupled mechanically with a position and angular speed sensor more particularly, the arrangement is of the kind comprising, for each phase of the stator winding, a switching circuit including, for example, a pair of thyristors or a pair of power transistors, preferably of complementary type, which are preceded by a pair of amplifying transistors coupled in parallel by their bases and by their emitters, and the operation of the various switching circuits being sequentially controlled from signals received from the sensor in such a way that the various phases of the stator winding are fed by a system for polyphase bidirectional currents of substantially sinusoidal appearance rising and falling in steps, at a rate of 12 steps per cycle in the case of a three-phase system, the frequency and phase angle of each of these currents thus being determined by the speed of the rotor of the motor and by its position relative to the stator.